Silk screen process press



March 21, 1961 lLMA SILK SCREEN PROCESS PRESS Filed Feb. 12, 1958 4Sheets-Sheet 1 INVENTOR. L 0 0/5 6/ LM A N BY 52 EK/EL WOLF HIS ATTORNEYMarch 21, 1961 G|LMAN SILK SCREEN PROCESS PRESS 4 Sheets-Sheet 2 FiledFeb. 12, 1958 INVENTOR. L 00/5 G/LMA/V BY ZE/(/L M/OLF H/S A TTORNEYMarch 21, 1961 GlLMAN SILK SCREEN PROCESS PRESS 4 Sheets-Sheet 3 FiledFeb. 12, 1958 March 21, 1961 G|LMAN 2,975,705

SILK SCREEN PROCESS PRESS Filed Feb. 12, 1958 4 Shets-Sheet 4 f ii E a Ii:

I! \J k H R H I H U R 1 i: Q1 1'' W I N t- INVENTOR. LOU/S G/LMAN BYZEK/EL WOLF HIS ATTORNEY SILK SCREEN PROCESS PRESS Louis Gilman,Newtonville, Mass. (80 Hampshire St., Boston 20, Mass.)

Filed Feb. 12, 1958, Ser. No. 714,728

7 Claims. c1.101--1zs) The present invention relates to an improvedpress particularly designed for silk screen process reproduction.

In silk processing it is extremely important to apply the squeegeeagainst the silk screen with uniform pressure over the entire stroke. Itis also important to coat the screen evenly with paint before thesqueegee makes its run.

The present invention sults' in a simplified and inexpensive press.

The present invention further provides a silk screen process pressdesigned to permit close registration in which the squeegee contacts thescreen while moving in one direction only, while an even coat of painton the screen is assured by the spreading action of a filler bar whichmoves across the screen when the squeegee is returned to its initialprinting position.

The present invention also provides a structure in which the squeegeepressure remains constant during the entire printing stroke. Thisfeature is obtained by forming the frame in which the squeegee isjournalled for reciprocal' movement with an angular section at initialprinting end of the stroke. This angular section carries the squeegeeaway from the screen when the screen is placed and locked in theprinting position. Upon the actuation of the printing stroke, thesqueegee is brought gradually into contact with the screen just prior tothe printing stroke so that a substantial pressure may be built upbetween the squeegee and screen before the printing stroke commences,which pressure is maintained during the entire stroke.

Further, the present invention provides an operating mechanism includingcam controlled cycling means which cooperate with the angular section ofthe frame to pro vide a rigid, interlock of the screen, frame andprinted material before the printing stroke commences but inv such amanner as to permit a gradual increase of pressure designedto obtainthese re- 2,975,705. Pat ented Mar. 21, 1961 therethrough (not shown) atthe other side of which may be connected means (also not shown) forproviding air suction through the holesso that any paper positioned onthe table top will be rigidly secured in place. On the top surface 10 ofthe inverted U-shaped supporting beam 3 is a gear box 11 having adriving shaft 12 and two preferably coaxial driven shafts f3 and 14which are operably responsive to rotation of shaft 12 with shafts 13 and14 rotating uniformly with respect to one another and in the samedirection. The driving shaft 12 is operatively connected to a drivemechanism (not shown) such as a constant speed motor through asuitablearrangement of the squeegee upon the screen just prior to theprinting stroke.

' These and other objects and advantages of the present invention willbe more clearly understood when considered in connection with theaccompanying drawings in which Figure 1 is a side plan view of theinvention with the screen in an open position;

Figure 2 is a side plan view of the invention with the screen in aclosed position, and the squeegee in position before its printingstroke; V

Figure 3 is a side plan view of the invention with the squeegee in anintermediate printing positionjand Figure 4 is an end plan view of theinvention taken from the left of Figure 2. j a

In this arrangement there is provided a suitable supporting frame whichmay comprise a series of structural angle members welded or otherwisesuitably secured to- I gether to form a supporting base for a tabletop 1. This such as a belt and pulley arrangement including a pulley asindicated at 15.

There is mounted on driven shaft 13 a cam 17 designed to engage therollerltl which in turn is pivotally supported to the lever arm 19intermediate its ends. -The lever arm 19 forms part of a lever linkagesystem Which-is operatively engaged to the channel frame 20 for thepurpose of raising and lowering this channel frame 20 to and from aprinting position, the channel frame also carrying with it the silkscreen, squeegee, and filler bar. The channel frame 20 'is mounted on apair of parallel supporting arms 21' toward'its rear end 9. Thesesupporting arms 21 extend normally from opposite sides of the channelframe 2d, and are rigidly secured by welding or other suitable means attheir lower ends to a shaft 22 which extends parallel to the plane ofthe frame 20. As the arms 21, shaft 22 and frame 28 are all rigidlyconnected, rotation of the shaft 22 will cause a pivoting movement ofthe frame toward and away from the table top 1. The ends of the shaft 22are suitably journalled in journal blocks 23, in turn secured to thebase of the press preferably on a level with the top 1. Also, rigidlysecured at one end to the shaft 22 is a lever arm 24 which also forms aportion of the aforementioned lever linkage system. An intermediatelever 25 is pivotally interconnected at one end 26 to the other end oflever 24 and at the other end 27 to the other end of lever 19. Theselevers 19 25 and 24 are so proportioned that when the frame 20 is indown position as illustrated in Figure 2, the levers l9 and 25 will belongitudinally aligned with the lever 24 substantially normal to thealigned levers 19 and 25. In this position, the channel frame 2i) issubstantially locked in position, for in order for it to pivot to anopen position it would have to work through the lever 24 against atheoretical infinite resistance of the levers 19 and 25, unlessthese'levers 19 and 25 are pivoted to a non aligned position at the end27. These levers 19, 25 and 24 are normally tensioned to this lockedposition by the weight of the frame 20. The levers however arecyclically moved from this position by the rotation of the cam 17 which,as indicated, engages the roller 18, thus providing a reciprocal pivotalmovement of the frame 2i Operating synchronously with the lever linkagesystem and frame 20 is the squeegee operating mechanism and filler bararrangement generally indicated at 30. This mechanism which Will be morefully described hereinafter reciprocates between the ends of the frameas through the operation of the mechanism generally indicated at 31.This mechanism 31 includes an elongated lever arm 32, pivotally securedat its lower end 33 to the member 34, in turn secured to the end-of beam3. The upper end of the lever arm 32 is pivotally interengaged with thelever arm 35 at 36. The lever arm 35 in turn pivotally engages andoperates the squeegee and filler bar mechanism through a pivotalconnection 37. Intermediate the ends of the lever arm 32 is pivotallyconnected the end of an operating lever 38, which also pivotally engagesat its other end the operating lever 39. The lever 39 is pivotallymounted at its other end on beam 3 in a suitable journal indicated at40. Intermediate the ends of the lever arm 39 is a roller 41. The roller41 engages the cam 42 (Figure 2) with the cam in turn pivotally mountedon the shaft 14. The roller 41 is normally maintained in contact withthe cam 42 through the tension of spring 43 whiclris suitably connectedat one end to the lever 32 and at the other end to the frame preferablyat the forward end, as indicated at 45.

Referring now to the channel frame 20, it will be observed that it isformed preferably U-shape with parallel side members 50 and 51 and anend member 53. Side members 50 and 51 (see Figure 4) provide inwardlyfacing channels within which the carriage 56 may reciprocally move.Particular attention is directed toward end portion 90 of the channelframe. It will be noted that this end portion 90 is formed slightlyangularly to the plane of the rear portion of the channel frame. Thisprovides means, as will be more fully referred to hereafter, of movingthe carriage angularly away from the screen and table top as it is movedforwardly toward the end 7 of the press. This carriage 56 comprises apair of transversely extending axles 57 having wheels or bearings 58mounted at each end thereof and adapted to slide back and forth withinthe channels. A pair of side members 59 on either side of the frameinterconnect the forward and rear axles 57. Also forming a portion ofeach side member is a downwardly extending angle member 60 which isrigidly interconnected with the side member 59. A shaft 61 extendsbetween the opposite downwardly extending members 60 and has pivotallymounted on it a support 62 to which a pair of parallel extensions 63 arerigidly secured. An adjusting screw 64 extends upwardly through eachextension 63 and threads into the carriage in such a manner as to permitthe pivotal movement of the extension 63 toward and away from the planeof the side members 59 by the expedient of adjusting the screws 64. Atthe forward end of the extension 63 there is provided a downwardlyturned end 66 which carries with it the squeegee 67. This squeegee 67comprises preferably a supporting block, as indicated at 69, with aresilient wiping member 70 extending longitudinally of and fittingwithin the block 69.

The lever 35, as indicated, is pivotally interconnected at end 37 to thecarriage mechanism. The short lever arm 71 is pivotally interconnectedat 37 at its upper end and at its lower end to the shaft 61. Extendingangularly forward from and rigidly connected to the lever 71intermediate its ends 37 and 61 is an operating arm 72. The forward endof this operating arm 72 pivotally supports an operating rod 73 at '74.The lower end of the operating rod 73 loosely engages the loop 75 inturn rigidly connected to the filler bar 76. This filler bar 76 isslidably mounted, as for example by a sleeve 78 attached to the tillerbar 76, on parallel rods 77 which are secured at their upper ends to thesides 59 by suitable means.

The lower edges of the squeegee 67 is adapted to engage the uppersurface of a silk screen secured to the bottom of the screen frame 80during the printing stroke. This screen frame 80 is preferablyrectangular in shape and is formed of four side members enclosing anopen center under which the screen is secured. One end, 81, is pivotallysecured by the hinge member 82 to the table top parallel to and just infront of the shaft 22. The other end of the frame 80 is looselyinterengaged with the forward end of the channel frame 20. Thisengagement is effected by a hook 84 secured at its lower end to theupper surface of the frame and a hook 85 secured at its upper end toextension 86 in turn secured to the forward side of the channel frame.The hooks 84 and 85 are loosely interengaged by a ring 87. Thus, as theframe 20 is raised, it will carry' with it frame 80 as illustrated inFigure 1, while still permitting the pivoting of the two members onseparate axes.

As previously indicated the end portion 90 is formed slightly angularlyto the plane of the rear portion of the channel frame. Thus, as thecarriage 56 moves to a forward position as the frame 20 is movingdownward to its locked position as illustrated in Figure 2, the squeegee67 at the foremost position will be raised away from the table top 1 andwill consequently be out of pressure contact with the screen mounted onthe frame 80. As the printing stroke progresses the carriage 56 movesrearwardly toward end 9, carrying with it the squeegee 67 which isspring loaded relative to the carriage by spring 64. Thus, as thecarriage is brought down into parallel alignment with the table top asthe carriage moves toward the rear portion of the frame, the squeegee 67will contact the screen and table top with substantial pressuredetermined by the adjustment of the screws coaxial with the springs 64.This substantial pressure will be uniformly maintained during the entireprinting stroke. It will be noted, however, that the pressure was notbuilt up until after the levers 19 and 25 were positioned in theirlocking positions (see particularly Figure 2).

When the squeegee has completely traversed the printing area of thescreen, the earns 17 and 42, which are synchronized, cause the raisingof the frame 20 and the screen which is attached to it in the manner asillustrated in Figure 1. While these members are raised the squeegee andfilter bar are returned to the initial printing position. During thisreturn action, however, the squeegee 67 is spaced from the screen whilethe filter bar is in contact with it (see Figure 1). This is due to aforward motion of the lever arm 35 which is translated into a downwardpressure on the filler bar 76. At the end of the cycle when the squeegeehas reached its initial printing position, the cam has returned theframe 20 and screen to the position as indicated in Figure 2.

Having now described my invention, I claim:

' 1. In a screen process press having a screen, a table top, meansmounting said screen for pivotal movement against said top, a squeegeeand means mounting said squeegee for movement into positive pressurecontact across said screen, the combination comprising channels at leastsubstantially as long as said screen within which said means mountingsaid squeegee is mounted, means for pivoting said channels into fixedparallel relation above said screen, end channel portions continuouswith said channels extending angularly away from said screen when saidchannels are in said fixed position with said channel portions adaptedto receive said squeegee mounting means at the beginning of saidmovement of said squeegee, and means for rigidly securing said channelsand channel portions in said position before the movement of saidsqueegee whereby said squeegee will be guided by said channel portionsand channels into a gradual positive pressure contact with said screenduring its movement and after said channel portions are secured in saidposition.

2. In a screen process press having a screen, a table top, meansmounting said screen for pivotal movement against said top, a squeegeeand guide means for guiding said squeegee for movement in positivepressure contact across said screen, the combination comprising meansfor securing said guide means and screen in fixed relation, and meansfor moving said squeegee across said screen, said guide means includingchannels having portions parallel to said screen and end portionsdiverging therefrom with said squeegee guided by said portions wherebymeans are provided for gradually building up the pressure contactbetween said squeegee and screen after said mounting means and screenare secured in fixed relation.

3.In a screen process press having a screen, a table top, means mountingsaid screen for pivotal movement against said top, a squeegee andguiding means for guiding said squeegee for movement into positivepressure contact across said screen, the combination comprising meansfor securing said guiding means and screen in fixed relation, means formoving said squeegee across said screen, said guiding means comprising aframe having an angular section adapted to guide said squeegee with oneportion adapted to be secured parallel to said screen for maintaininguniform positive pressure between said squeegee and screen along saidportion and a second port-ion diverging om said screen adapted toprovide an initial gradual increase in pressure contact between saidscreen and squeegee.

4. A device as set forth in claim 3 wherein said means for securing saidguiding means comprises a lever linkage system adapted also to pivotsaid guiding means to and from parallel alignment with said top, saidsystem having a pair of longitudinally aligned levers providing aninfinite resistance against pivotal movement of said securing means whensaid securing means is parallel with said top.

5. A device as set forth in claim 3 wherein said means for securing saidguiding means comprises a lever linkage system having a pair ofinterengaged levers fixed at one end and pivotally engaging at the otheran extension of said guiding means, said levers adapted to belongitudinally aligned when said guiding means are parallel to the topthereby presenting an infinite resistance to movement of said guidingmeans, and a cam engaging said levers for movement thereof to and fromsaid aligned position,

6. A device as set forth in claim 5 providing a second cam and means foroperating said cams in synchronism, said second cam operatively engagingsaid means for moving said squeegee.

7. A silk screen process press comprising a frame, a horizontallydisposed work receiving surface secured to said frame, a silk screen, arectangular frame mounting said screen, means for pivoting said screenabout one edge into facing relation with said surface, an elongatedsqueegee guide means having opposed parallel elongated channel portionsat least substantially as long as said screen and having continuousangular end portions, means pivotally mounting said elongated channelportions at,

one end for pivotal movement to and from a parallel position withrespect to said facing relation position of said screen, with said endportions. gradually diverging therefrom, an elongated squeegee, meansmounting said squeegee between said parallel portions for slideablemovement therealong, means for sliding said last mentioned means fromsaid end portion along said channel portions whereby said squeegee maybe guided by said end channel portions into a gradual positive pressurecontact with said screen, and means for rigidly securing said channelportions and screen in fixed relation before actuation of said lastmentioned means.

References Cited in the file of this patent UNITED STATES PATENTS1,843,116 Aldcroftt et a1. Feb. 2, 1932 2,229,346 Shurley Jan. 21, 19412,321,134 Fleisher et a1. June 8, 1943 2,581,775 Wade Jan. 8, 19522,588,878 Reemelin Mar. 11, 1952 2,704,510 Walsh Mar. 22, 1955 2,894,451Landesman July 14, 1959

